r241729 - CodeGen: Fix off-by-one error in CFI class identification function for MS ABI.

[Peter Collingbourne]

Author: pcc
Date: Wed Jul  8 16:08:08 2015
New Revision: 241729

URL: http://llvm.org/viewvc/llvm-project?rev=241729&view=rev
Log:
CodeGen: Fix off-by-one error in CFI class identification function for MS ABI.

We were previously ignoring classes laid out at offset zero.

Modified:
    cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp
    cfe/trunk/test/CodeGenCXX/cfi-vcall.cpp

Modified: cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp?rev=241729&r1=241728&r2=241729&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp Wed Jul  8 16:08:08 2015
@@ -1707,7 +1707,7 @@ static const CXXRecordDecl *getClassAtVT
   for (auto &&B : RD->bases()) {
     const CXXRecordDecl *Base = B.getType()->getAsCXXRecordDecl();
     CharUnits BaseOffset = Layout.getBaseClassOffset(Base);
-    if (BaseOffset <= Offset && BaseOffset > MaxBaseOffset) {
+    if (BaseOffset <= Offset && BaseOffset >= MaxBaseOffset) {
       MaxBase = Base;
       MaxBaseOffset = BaseOffset;
     }
@@ -1715,7 +1715,7 @@ static const CXXRecordDecl *getClassAtVT
   for (auto &&B : RD->vbases()) {
     const CXXRecordDecl *Base = B.getType()->getAsCXXRecordDecl();
     CharUnits BaseOffset = Layout.getVBaseClassOffset(Base);
-    if (BaseOffset <= Offset && BaseOffset > MaxBaseOffset) {
+    if (BaseOffset <= Offset && BaseOffset >= MaxBaseOffset) {
       MaxBase = Base;
       MaxBaseOffset = BaseOffset;
     }

Modified: cfe/trunk/test/CodeGenCXX/cfi-vcall.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/cfi-vcall.cpp?rev=241729&r1=241728&r2=241729&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/cfi-vcall.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/cfi-vcall.cpp Wed Jul  8 16:08:08 2015
@@ -134,6 +134,29 @@ void foo() {
   af(&fa);
 }
 
+namespace test2 {
+
+struct A {
+  virtual void m_fn1();
+};
+struct B {
+  virtual void m_fn2();
+};
+struct C : B, A {};
+struct D : C {
+  void m_fn1();
+};
+
+// ITANIUM: define void @_ZN5test21fEPNS_1DE
+// MS: define void @"\01?f at test2@@YAXPEAUD at 1@@Z"
+void f(D *d) {
+  // ITANIUM: {{%[^ ]*}} = call i1 @llvm.bitset.test(i8* {{%[^ ]*}}, metadata !"N5test21DE")
+  // MS: {{%[^ ]*}} = call i1 @llvm.bitset.test(i8* {{%[^ ]*}}, metadata !"A at test2@@")
+  d->m_fn1();
+}
+
+}
+
 // Check for the expected number of elements (9 or 15 respectively).
 // MS: !llvm.bitsets = !{[[X:[^,]*(,[^,]*){8}]]}
 // ITANIUM: !llvm.bitsets = !{[[X:[^,]*(,[^,]*){14}]]}